Various prosthetic mesh materials have been proposed to reinforce the abdominal wall and to close abdominal wall defects. It has been known to fold a sheet of surgical mesh fabric into the multilayer cone configuration and then to insert the mesh plug into a hernia defect to occlude the void. One example of a mesh plug for occluding voids in tissue walls caused by herniation and the like is the Perfix® Plug commercially available from C. R. Bard, Inc. of Murray Hill, N.J., USA.
These types of plugs often are formed of a plurality of layers of mesh material that are sewn together in order to give the plug suitable structural rigidity and bulk. U.S. Pat. No. 5,356,432, which is incorporated herein fully by reference, discloses one such exemplary plug comprised of three layers of mesh material and a method of repairing muscle or tissue wall defects using such a plug. FIG. 1 herein is an exploded perspective view of one exemplary plug 10 disclosed in that patent. As can be seen, the plug comprises three layers of material 12, 14, and 16. Plug layer 12 is composed of a generally circular piece of a mesh fabric folded into a conical plug shape and bearing a plurality of pleats. Layers 14 and 16 are inner filler layers that, when the plug is assembled, are disposed inside of the outer, plug layer 12 and attached at their bases (i.e., their geometric centers) 30 to the center (or tip) 20 of outer layer 12. The circular outer plug layer 12 provides a continuous mesh piece to effectively plug the hole, while each of layers 14 and 16 provides structural rigidity and bulk to the overall prosthesis 10.
With reference to FIG. 2, layers 14 and 16 typically are formed by cutting out a circular piece 31 of the mesh material similar in size to that of the plug body 12 and then cutting out pie-shaped wedges (not shown) radially around the circular piece 31 so as to leave a plurality of petals 28 surrounding a central base 30.
Typically, the mesh material for fabricating such plugs is supplied in rectangular sheets. Accordingly, in order to cut out the circular outer layer 12 and the two filler layers 14 and 16, a significant amount of the original rectangular sheet of material is discarded, e.g., the pie-shaped pieces cut out of the originally circular filler pieces as well as the areas between all of the circular pieces.
The hernia plug industry is generally moving toward the use of more expensive mesh materials with superior qualities, such that the cost of the mesh material is becoming a more significant factor in the overall cost of the prostheses.